Centralize hardcoded magic numbers into CONFIG dict

Move NEW_DRIVE_HOURS_THRESHOLD (720h) and SMART_ERROR_RECENT_HOURS (168h)
from inline literals to configurable CONFIG entries with .env support.

Resolves #20

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

hwmonDaemon.py

@@ -124,7 +124,10 @@ class SystemHealthMonitor:
         # Prometheus metrics settings
         'PROMETHEUS_ENABLED': False,  # Enable Prometheus metrics export
         'PROMETHEUS_PORT': 9101,  # Port for Prometheus metrics HTTP server
-        'PROMETHEUS_TEXTFILE_PATH': None  # Path for textfile collector (alternative to HTTP)
+        'PROMETHEUS_TEXTFILE_PATH': None,  # Path for textfile collector (alternative to HTTP)
+        # SMART analysis thresholds
+        'NEW_DRIVE_HOURS_THRESHOLD': 720,    # Hours to consider a drive "new" (~30 days)
+        'SMART_ERROR_RECENT_HOURS': 168      # Hours window for recent SMART errors (~1 week)
     }
 
     @classmethod
@@ -182,6 +185,10 @@ class SystemHealthMonitor:
                         elif key == 'CLUSTER_NAME':
                             cls.CONFIG['CLUSTER_NAME'] = value if value else 'proxmox-cluster'
                             logger.info(f"✓ Loaded CLUSTER_NAME: {value}")
+                        elif key == 'NEW_DRIVE_HOURS_THRESHOLD':
+                            cls.CONFIG['NEW_DRIVE_HOURS_THRESHOLD'] = int(value)
+                        elif key == 'SMART_ERROR_RECENT_HOURS':
+                            cls.CONFIG['SMART_ERROR_RECENT_HOURS'] = int(value)
 
         except Exception as e:
             logger.error(f"Failed to load .env file: {e}")
@@ -2266,7 +2273,7 @@ class SystemHealthMonitor:
 
     def _is_new_drive(self, power_on_hours: int) -> bool:
         """Determine if a drive is considered "new" based on power-on hours."""
-        return power_on_hours < 720  # Less than 1 week of runtime
+        return power_on_hours < self.CONFIG['NEW_DRIVE_HOURS_THRESHOLD']
 
     def _check_smart_health(self, device: str) -> Dict[str, Any]:
         """Enhanced SMART health check with better error handling and predictive analysis."""
@@ -2501,7 +2508,7 @@ class SystemHealthMonitor:
             for match in error_matches:
                 error_hour = int(match.group(1))
                 current_hours = smart_health['attributes'].get('Power_On_Hours', 0)
-                if current_hours - error_hour < 168:  # Errors within last week
+                if current_hours - error_hour < self.CONFIG['SMART_ERROR_RECENT_HOURS']:
                     recent_errors.append(match.group(0))
 
             if recent_errors: